Mariehamn weather in December
Temperature, sea and sunshine in December: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in December
Poor
Best time to visit: June – August
What is the weather like in Mariehamn in December?
In December, Mariehamn is freezing cold: daytime highs average 3 °C, and nights cool down to about 0 °C. The sea averages 4.3 °C – swimming is only for the hardy. The sun is scarce, with only about 1 hours a day. Precipitation, often as snow, falls on about 11 days, totalling 46 mm. Snow falls on about 4 days. All in all, December is not an ideal month for a holiday in Mariehamn.
December compared
How the weather changes from November to January. Tap a month to open it.
| NovemberNov | DecemberDec | JanuaryJan | |
|---|---|---|---|
| Score | 17 | 14 | 19 |
| Day | 6° | 3° | 1° |
| Night | 4° | 0° | −2° |
| Sea | 7° | 4° | 2° |
| Sun | 1 h | 1 h | 1 h |
| Rain days | 10 | 11 | 9 |
More details for December
- Daylight
- 5 h 55 min09:38 – 15:33
- UV index
- 0 · lowclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or moreAll months
- Wind
- 28 km/haverage daily peakAll months
- Cloud cover
- 79 %on averageAll months
- Hot days
- 0 days30 °C or more
- Snow days
- 4 days1 cm or more of fresh snowAll months
- Time zone
- UTC+2Europe/Mariehamn
How the score comes together
- Temperatureweight 50 %0 %
- Sunshineweight 20 %0 %
- Few rainy daysweight 30 %47 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in December
- Warm jacket
- Hat, scarf & gloves
- Rain jacket or umbrella
Mariehamn in December: quick answers
Is Mariehamn hot in December?
No. In December, Mariehamn is freezing cold: daytime highs average 3 °C and nights drop to about 0 °C.
Can you swim in Mariehamn in December?
Only if you don't mind cold water: in December the sea averages just 4.3 °C. Comfortable swimming temperatures are not reached at any time of year.
Does it rain much in Mariehamn in December?
Rain is frequent, with about 11 rainy days and 46 mm in total.
Mariehamn month by month
The whole year in MariehamnAll destinations: Åland IslandsWhere to go in DecemberSea temperature in December
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences